MP07-20 INITIAL EXPERIENCE: EX-VIVO PERFUSED PIG KIDNEY TO STUDY URINARY OXALATE EXCRETION

Abstract

You have accessJournal of UrologyStone Disease: Basic Research & Pathophysiology (MP07)1 Sep 2021MP07-20 INITIAL EXPERIENCE: EX-VIVO PERFUSED PIG KIDNEY TO STUDY URINARY OXALATE EXCRETION Jonathan Pavlinec, Mark Martin, William Donelan, Elizabeth Kwenda, Paul Dominguez-Gutierrez, Vincent Bird, and Benjamin Canales Jonathan PavlinecJonathan Pavlinec More articles by this author , Mark MartinMark Martin More articles by this author , William DonelanWilliam Donelan More articles by this author , Elizabeth KwendaElizabeth Kwenda More articles by this author , Paul Dominguez-GutierrezPaul Dominguez-Gutierrez More articles by this author , Vincent BirdVincent Bird More articles by this author , and Benjamin CanalesBenjamin Canales More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001980.20AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Existing animal models of renal oxalate excretion utilize either gut or peritoneal cavity for oxalate absorption. Ex vivo renal perfusion is an established tool for graft preservation. We sought to repurpose this concept in order to study the early pathogenesis of urinary lithiasis. METHODS: Juvenile female Yorkshire porcine kidneys were removed laparoscopically and placed on an ex vivo neonatal cardiopulmonary bypass circuit utilizing whole-blood based perfusate oxygenated with 95% carbogen. Pre-defined goals were identified for each attempt (n=5) with plans to increase physiologic model complexity. Tissue perfusion and oxygenation was monitored by serial perfusate iSTAT testing. Once steady urine production was achieved, aqueous oxalate was injected into the perfusate. Renal outcomes were assessed by histology and blood/urinary assays. RESULTS: After demonstrating proof-of-concept in early trials, normothermic (37C) ex vivo whole-blood perfusion with Steen SolutionTM was performed exceeding three hours at physiologic mean arterial pressures. Circuit parameters remained in the physiologic range for electrolytes, temperature, mean arterial pressure, lactate, and pH. Urine was produced in three experiments, with two additional attempts stopped early due to challenges related to hilar cannulation. Urinary filtrate demonstrated consistently higher urine creatinine compared to perfusate, and arterial perfusate oxalate boluses lead to urinary oxalate spikes followed by continuous oxalate clearance. Histopathologic analysis with H&E and Pizzolato’s method staining demonstrated formation of calcium oxalate crystals. CONCLUSIONS: In light of promising renal urinary oxalate and creatinine clearance, ex vivo porcine renal perfusion appears to be a feasible alternative to study oxalate excretion. Longer validation studies are necessary to establish this technique as a model for kidney stone pathogenesis. Source of Funding: No extra-instatutional funding was utilized for this project © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e147-e148 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jonathan Pavlinec More articles by this author Mark Martin More articles by this author William Donelan More articles by this author Elizabeth Kwenda More articles by this author Paul Dominguez-Gutierrez More articles by this author Vincent Bird More articles by this author Benjamin Canales More articles by this author Expand All Advertisement Loading ...